wayland: Add xx-session-management-v1 supportHEADdev

This is powered by the xx-session-manager which is tagged as
experiemntal. This is guarded by an env variable.

Application level session IDs are exposed via QSessionManager.

The public API for windows is exposed via the existing QSessionManager
and QWidget::setWindowRole.

As it's not widely supported the documentation in QWidget is left
untouched for now.

[ChangeLog][Third-Party Code] New protocol synced from wayland-protocols

Change-Id: Ibfbef86c6e75f8b95433cbba69ca10a5abea9e21
Reviewed-by: Vlad Zahorodnii <[email protected]>

16 files changed, 539 insertions, 4 deletions

diff --git a/src/3rdparty/wayland/protocols/session-management/REUSE.toml b/src/3rdparty/wayland/protocols/session-management/REUSE.toml
new file mode 100644
index 00000000000..585706d8fcd
--- /dev/null
+++ b/src/3rdparty/wayland/protocols/session-management/REUSE.toml
@@ -0,0 +1,12 @@
+version = 1
+
+[[annotations]]
+path = "xx-session-management-v1.xml"
+precedence = "closest"
+SPDX-FileCopyrightText = [
+    "Copyright 2018 Mike Blumenkrantz",
+    "Copyright 2018 Samsung Electronics Co., Ltd",
+    "Copyright 2018 Red Hat Inc."
+]
+
+SPDX-License-Identifier = "MIT"
diff --git a/src/3rdparty/wayland/protocols/session-management/qt_attribution.json b/src/3rdparty/wayland/protocols/session-management/qt_attribution.json
new file mode 100644
index 00000000000..8539749f112
--- /dev/null
+++ b/src/3rdparty/wayland/protocols/session-management/qt_attribution.json
@@ -0,0 +1,17 @@
+[
+    {
+        "Id": "wayland-session-management-protocol",
+        "Name": "Wayland Session Management Protocol",
+        "QDocModule": "qtwaylandcompositor",
+        "QtUsage": "Used in the Qt Wayland platform plugin.",
+        "Files": "xx-session-management-v1.xml",
+        "Description": "An extension to restore window positions",
+        "Homepage": "https://wayland.freedesktop.org/",
+        "Version": "experimental V1",
+        "DownloadLocation": "https://gitlab.freedesktop.org/wayland/wayland-protocols/-/blob/main/experimental/xx-session-management/xx-session-management-v1.xml?ref_type=heads",
+        "LicenseId": "MIT",
+        "License": "MIT License",
+        "LicenseFile": "../MIT_LICENSE.txt",
+        "Copyright": "Copyright 2018 Mike Blumenkrantz\nCopyright 2018 Samsung Electronics Co., Ltd\nCopyright 2018 Red Hat Inc."
+    }
+]
diff --git a/src/3rdparty/wayland/protocols/session-management/xx-session-management-v1.xml b/src/3rdparty/wayland/protocols/session-management/xx-session-management-v1.xml
new file mode 100644
index 00000000000..42458d9291a
--- /dev/null
+++ b/src/3rdparty/wayland/protocols/session-management/xx-session-management-v1.xml
@@ -0,0 +1,264 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="xx_session_management_v1">
+  <copyright>
+    Copyright 2018 Mike Blumenkrantz
+    Copyright 2018 Samsung Electronics Co., Ltd
+    Copyright 2018 Red Hat Inc.
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <description summary="Protocol for managing application sessions">
+    This description provides a high-level overview of the interplay between
+    the interfaces defined this protocol. For details, see the protocol
+    specification.
+
+    The xx_session_manager protocol declares interfaces necessary to
+    allow clients to restore toplevel state from previous executions. The
+    xx_session_manager_v1.get_session request can be used to obtain a
+    xx_session_v1 resource representing the state of a set of toplevels.
+
+    Clients may obtain the session string to use in future calls through
+    the xx_session_v1.created event. Compositors will use this string
+    as an identifiable token for future runs, possibly storing data about
+    the related toplevels in persistent storage.
+
+    Toplevels are managed through the xx_session_v1.add_toplevel and
+    xx_session_toplevel_v1.remove pair of requests. Clients will explicitly
+    request a toplevel to be restored according to prior state through the
+    xx_session_v1.restore_toplevel request before the toplevel is mapped.
+
+    Warning! The protocol described in this file is currently in the
+    experimental phase. Backwards incompatible major versions of the
+    protocol are to be expected. Exposing this protocol without an opt-in
+    mechanism is discouraged.
+  </description>
+
+  <interface name="xx_session_manager_v1" version="1">
+    <description summary="manage sessions for applications">
+      The xx_session_manager interface defines base requests for creating and
+      managing a session for an application. Sessions persist across application
+      and compositor restarts unless explicitly destroyed. A session is created
+      for the purpose of maintaining an application's xdg_toplevel surfaces
+      across compositor or application restarts. The compositor should remember
+      as many states as possible for surfaces in a given session, but there is
+      no requirement for which states must be remembered.
+    </description>
+
+    <enum name="error">
+      <entry name="in_use" summary="a requested session is already in use"
+             value="1"/>
+    </enum>
+
+    <enum name="reason">
+      <description summary="reason for getting a session">
+        The reason may determine in what way a session restores the window
+        management state of associated toplevels.
+
+        For example newly launched applications might be launched on the active
+        workspace with restored size and position, while a recovered
+        applications might restore additional state such as active workspace and
+        stacking order.
+      </description>
+      <entry name="launch" value="1">
+        <description summary="an app is newly launched">
+          A new app instance is launched, for example from an app launcher.
+        </description>
+      </entry>
+      <entry name="recover" value="2">
+        <description summary="an app recovered">
+          A app instance is recovering from for example a compositor or app crash.
+        </description>
+      </entry>
+      <entry name="session_restore" value="3">
+        <description summary="an app restored">
+          A app instance is restored, for example part of a restored session, or
+          restored from having been temporarily terminated due to resource
+          constraints.
+        </description>
+      </entry>
+    </enum>
+
+    <request name="destroy" type="destructor">
+      <description summary="Destroy this object">
+        This has no effect other than to destroy the xx_session_manager object.
+      </description>
+    </request>
+
+    <request name="get_session">
+      <description summary="create or restore a session">
+        Create a session object corresponding to either an existing session
+        identified by the given session identifier string or a new session.
+        While the session object exists, the session is considered to be "in
+        use".
+
+        If a identifier string represents a session that is currently actively
+        in use by the the same client, an 'in_use' error is raised. If some
+        other client is currently using the same session, the new session will
+        replace managing the associated state.
+
+        NULL is passed to initiate a new session. If an id is passed which does
+        not represent a valid session, the compositor treats it as if NULL had
+        been passed.
+
+        A client is allowed to have any number of in use sessions at the same
+        time.
+      </description>
+      <arg name="id" type="new_id" interface="xx_session_v1"/>
+      <arg name="reason" type="uint" enum="reason"
+           summary="reason for session"/>
+      <arg name="session" type="string"
+           summary="the session to restore"
+           allow-null="true"/>
+    </request>
+  </interface>
+
+  <interface name="xx_session_v1" version="1">
+    <description summary="A session for an application">
+      A xx_session_v1 object represents a session for an application. While the
+      object exists, all surfaces which have been added to the session will
+      have states stored by the compositor which can be reapplied at a later
+      time. Two sessions cannot exist for the same identifier string.
+
+      States for surfaces added to a session are automatically updated by the
+      compositor when they are changed.
+
+      Surfaces which have been added to a session are automatically removed from
+      the session if xdg_toplevel.destroy is called for the surface.
+    </description>
+
+    <enum name="error">
+      <entry name="invalid_restore"
+             summary="restore cannot be performed after initial toplevel commit"
+             value="1"/>
+      <entry name="name_in_use"
+             summary="toplevel name is already in used"
+             value="2"/>
+      <entry name="already_mapped"
+             summary="toplevel was already mapped when restored"
+             value="3"/>
+    </enum>
+
+    <request name="destroy" type="destructor">
+      <description summary="Destroy the session">
+        Destroy a session object, preserving the current state but not continuing
+        to make further updates if state changes occur. This makes the associated
+        xx_toplevel_session_v1 objects inert.
+      </description>
+    </request>
+
+    <request name="remove" type="destructor">
+      <description summary="Remove the session">
+        Remove the session, making it no longer available for restoration. A
+        compositor should in response to this request remove the data related to
+        this session from its storage.
+      </description>
+    </request>
+
+    <request name="add_toplevel">
+      <description summary="add a new surface to the session">
+        Attempt to add a given surface to the session. The passed name is used
+        to identify what window is being restored, and may be used store window
+        specific state within the session.
+
+        Calling this with a toplevel that is already managed by the session with
+        the same associated will raise an in_use error.
+      </description>
+      <arg name="id" type="new_id" interface="xx_toplevel_session_v1"/>
+      <arg name="toplevel" type="object" interface="xdg_toplevel"/>
+      <arg name="name" type="string"/>
+    </request>
+
+    <request name="restore_toplevel">
+      <description summary="restore a surface state">
+        Inform the compositor that the toplevel associated with the passed name
+        should have its window management state restored.
+
+        Calling this with a toplevel that is already managed by the session with
+        the same associated will raise an in_use error.
+
+        This request must be called prior to the first commit on the associated
+        wl_surface, otherwise an already_mapped error is raised.
+
+        As part of the initial configure sequence, if the toplevel was
+        successfully restored, a xx_toplevel_session_v1.restored event is
+        emitted. See the xx_toplevel_session_v1.restored event for further
+        details.
+      </description>
+      <arg name="id" type="new_id" interface="xx_toplevel_session_v1"/>
+      <arg name="toplevel" type="object" interface="xdg_toplevel"/>
+      <arg name="name" type="string"/>
+    </request>
+
+    <event name="created">
+      <description summary="newly-created session id">
+        Emitted at most once some time after getting a new session object. It
+        means that no previous state was restored, and a new session was created.
+        The passed id can be used to restore previous sessions.
+      </description>
+      <arg name="id" type="string"/>
+    </event>
+
+    <event name="restored">
+      <description summary="the session has been restored">
+        Emitted at most once some time after getting a new session object. It
+        means that previous state was at least partially restored. The same id
+        can again be used to restore previous sessions.
+      </description>
+    </event>
+
+    <event name="replaced">
+      <description summary="the session has been restored">
+        Emitted at most once, if the session was taken over by some other
+        client. When this happens, the session and all its toplevel session
+        objects become inert, and should be destroyed.
+      </description>
+    </event>
+  </interface>
+
+  <interface name="xx_toplevel_session_v1" version="1">
+    <request name="destroy" type="destructor">
+      <description summary="Destroy the object">
+        Destroy the object. This has no effect window management of the
+        associated toplevel.
+      </description>
+    </request>
+
+    <request name="remove" type="destructor">
+      <description summary="remove a surface from the session">
+        Remove a specified surface from the session and render any corresponding
+        xx_toplevel_session_v1 object inert. The compositor should remove any
+        data related to the toplevel in the corresponding session from its internal
+        storage.
+      </description>
+    </request>
+
+    <event name="restored">
+      <description summary="a toplevel's session has been restored">
+        The "restored" event is emitted prior to the first
+        xdg_toplevel.configure for the toplevel. It will only be emitted after
+        xx_session_v1.restore_toplevel, and the initial empty surface state has
+        been applied, and it indicates that the surface's session is being
+        restored with this configure event.
+      </description>
+      <arg name="surface" type="object" interface="xdg_toplevel"/>
+    </event>
+  </interface>
+</protocol>
diff --git a/src/gui/kernel/qplatformwindow_p.h b/src/gui/kernel/qplatformwindow_p.h
index 5ee14c90e8a..c446ac760c0 100644
--- a/src/gui/kernel/qplatformwindow_p.h
+++ b/src/gui/kernel/qplatformwindow_p.h
@@ -135,6 +135,7 @@ public:
         auto role = std::any_cast<T *>(&anyRole);
         return role ? *role : nullptr;
     }
+    virtual void setSessionRestoreId(const QString &role) = 0;
 Q_SIGNALS:
     void surfaceCreated();
     void surfaceDestroyed();
diff --git a/src/plugins/platforms/wayland/CMakeLists.txt b/src/plugins/platforms/wayland/CMakeLists.txt
index 32a4ae34228..254a43c0dc6 100644
--- a/src/plugins/platforms/wayland/CMakeLists.txt
+++ b/src/plugins/platforms/wayland/CMakeLists.txt
@@ -77,6 +77,7 @@ qt_internal_add_module(WaylandClient
         qwaylandplatformservices.cpp qwaylandplatformservices_p.h
         qwaylandpointergestures.cpp qwaylandpointergestures_p.h
         qwaylandscreen.cpp qwaylandscreen_p.h
+        qwaylandsessionmanager.cpp qwaylandsessionmanager_p.h
         qwaylandshellsurface.cpp qwaylandshellsurface_p.h
         qwaylandshm.cpp qwaylandshm_p.h
         qwaylandshmbackingstore.cpp qwaylandshmbackingstore_p.h
@@ -124,6 +125,8 @@ qt_internal_add_module(WaylandClient
         ../../../3rdparty/wayland/protocols/viewporter
         ../../../3rdparty/wayland/protocols/xdg-shell
         ../../../3rdparty/wayland/protocols/wlr-data-control
+        ../../../3rdparty/wayland/protocols/session-management
+
 )
 
 qt_internal_add_plugin(QWaylandIntegrationPlugin
@@ -164,6 +167,7 @@ qt6_generate_wayland_protocol_client_sources(WaylandClient
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/wayland/extensions/server-buffer-extension.xml
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/wayland/protocols/color-management/xx-color-management-v4.xml
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/wayland/protocols/pointer-warp/pointer-warp-v1.xml
+        ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/wayland/protocols/session-management/xx-session-management-v1.xml
 )
 
 #### Keys ignored in scope 1:.:.:client.pro:<TRUE>:
diff --git a/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp b/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
index 1356d93abab..9c40103d1e5 100644
--- a/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
+++ b/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp
@@ -8,6 +8,7 @@
 #include "qwaylandxdgexporterv2_p.h"
 #include "qwaylandxdgdialogv1_p.h"
 #include "qwaylandxdgtopleveliconv1_p.h"
+#include "qwaylandsessionmanager_p.h"
 
 #include <QtWaylandClient/private/qwaylanddisplay_p.h>
 #include <QtWaylandClient/private/qwaylandwindow_p.h>
@@ -23,6 +24,16 @@ QT_BEGIN_NAMESPACE
 
 namespace QtWaylandClient {
 
+template <typename T, auto f>
+struct WithDestructor : public T
+{
+    using T::T;
+    ~WithDestructor()
+    {
+        f(this->object());
+    }
+};
+
 QWaylandXdgSurface::Toplevel::Toplevel(QWaylandXdgSurface *xdgSurface)
     : QtWayland::xdg_toplevel(xdgSurface->get_toplevel())
     , m_xdgSurface(xdgSurface)
@@ -45,6 +56,12 @@ QWaylandXdgSurface::Toplevel::Toplevel(QWaylandXdgSurface *xdgSurface)
         m_xdgDialog.reset(m_xdgSurface->m_shell->m_xdgDialogWm->getDialog(object()));
         m_xdgDialog->set_modal();
     }
+
+#ifndef QT_NO_SESSIONMANAGER
+    const QString sessionRestoreId = xdgSurface->window()->sessionRestoreId();
+    if (!sessionRestoreId.isEmpty() && QWaylandSessionManager::instance()->session())
+        m_session.reset(new WithDestructor<QtWayland::xx_toplevel_session_v1, xx_toplevel_session_v1_destroy>(QWaylandSessionManager::instance()->session()->restore_toplevel(object(), sessionRestoreId)));
+#endif
 }
 
 QWaylandXdgSurface::Toplevel::~Toplevel()
diff --git a/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell_p.h b/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell_p.h
index 236d34c351c..4595940508c 100644
--- a/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell_p.h
+++ b/src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell_p.h
@@ -30,6 +30,10 @@
 
 QT_BEGIN_NAMESPACE
 
+namespace QtWayland {
+    class xx_toplevel_session_v1;
+}
+
 namespace QtWaylandClient {
 
 class QWaylandDisplay;
@@ -41,6 +45,7 @@ class QWaylandXdgExporterV2;
 class QWaylandXdgDialogWmV1;
 class QWaylandXdgDialogV1;
 class QWaylandXdgToplevelIconManagerV1;
+class QWaylandTopLevelSession;
 
 class Q_WAYLANDCLIENT_EXPORT QWaylandXdgSurface : public QWaylandShellSurface, public QtWayland::xdg_surface
 {
@@ -114,6 +119,7 @@ private:
         QWaylandXdgToplevelDecorationV1 *m_decoration = nullptr;
         QScopedPointer<QWaylandXdgExportedV2> m_exported;
         QScopedPointer<QWaylandXdgDialogV1> m_xdgDialog;
+        QScopedPointer<QtWayland::xx_toplevel_session_v1> m_session;
     };
 
     class Positioner : public QtWayland::xdg_positioner {
diff --git a/src/plugins/platforms/wayland/qwaylanddisplay.cpp b/src/plugins/platforms/wayland/qwaylanddisplay.cpp
index 071ad78f91c..d853fc673e5 100644
--- a/src/plugins/platforms/wayland/qwaylanddisplay.cpp
+++ b/src/plugins/platforms/wayland/qwaylanddisplay.cpp
@@ -53,6 +53,7 @@
 #include <QtWaylandClient/private/qwayland-fractional-scale-v1.h>
 #include <QtWaylandClient/private/qwayland-viewporter.h>
 #include <QtWaylandClient/private/qwayland-cursor-shape-v1.h>
+#include <QtWaylandClient/private/qwayland-xx-session-management-v1.h>
 #include <QtWaylandClient/private/qwayland-xdg-system-bell-v1.h>
 #include <QtWaylandClient/private/qwayland-xdg-toplevel-drag-v1.h>
 #include <QtWaylandClient/private/qwayland-wlr-data-control-unstable-v1.h>
@@ -803,6 +804,14 @@ void QWaylandDisplay::registry_global(uint32_t id, const QString &interface, uin
         mGlobals.pointerWarp.reset(new WithDestructor<QtWayland::wp_pointer_warp_v1, wp_pointer_warp_v1_destroy>(
                 registry, id, 1));
     }
+#ifndef QT_NO_SESSIONMANAGER
+       else if (interface == QLatin1String(QtWayland::xx_session_manager_v1::interface()->name)
+               && qEnvironmentVariableIntValue("QT_WAYLAND_ENABLE_XX_SESSION_MANAGER") > 0) {
+        mGlobals.xxSessionManager.reset(
+                new WithDestructor<QtWayland::xx_session_manager_v1, xx_session_manager_v1_destroy>(
+                        registry, id, 1));
+    }
+#endif
 
 
     mRegistryGlobals.append(RegistryGlobal(id, interface, version, registry));
diff --git a/src/plugins/platforms/wayland/qwaylanddisplay_p.h b/src/plugins/platforms/wayland/qwaylanddisplay_p.h
index 29952886421..91d3497fe51 100644
--- a/src/plugins/platforms/wayland/qwaylanddisplay_p.h
+++ b/src/plugins/platforms/wayland/qwaylanddisplay_p.h
@@ -56,6 +56,7 @@ namespace QtWayland {
     class wp_cursor_shape_manager_v1;
     class wp_fractional_scale_manager_v1;
     class wp_viewporter;
+    class xx_session_manager_v1;
     class xdg_system_bell_v1;
     class xdg_toplevel_drag_manager_v1;
     class wp_pointer_warp_v1;
@@ -86,6 +87,7 @@ class QWaylandPointerGestures;
 class QWaylandWindow;
 class QWaylandIntegration;
 class QWaylandHardwareIntegration;
+class QWaylandSessionManager;
 class QWaylandSurface;
 class QWaylandShellIntegration;
 class QWaylandCursor;
@@ -214,6 +216,10 @@ public:
     {
         return mGlobals.xdgToplevelDragManager.get();
     }
+    QtWayland::xx_session_manager_v1 *xxSessionManager() const
+    {
+        return mGlobals.xxSessionManager.get();
+    }
     QtWayland::xdg_system_bell_v1 *systemBell() const
     {
         return mGlobals.systemBell.get();
@@ -360,6 +366,7 @@ private:
         std::unique_ptr<QtWayland::wp_viewporter> viewporter;
         std::unique_ptr<QtWayland::wp_fractional_scale_manager_v1> fractionalScaleManager;
         std::unique_ptr<QtWayland::wp_cursor_shape_manager_v1> cursorShapeManager;
+        std::unique_ptr<QtWayland::xx_session_manager_v1> xxSessionManager;
         std::unique_ptr<QtWayland::xdg_system_bell_v1> systemBell;
         std::unique_ptr<QtWayland::xdg_toplevel_drag_manager_v1> xdgToplevelDragManager;
         std::unique_ptr<QWaylandWindowManagerIntegration> windowManagerIntegration;
diff --git a/src/plugins/platforms/wayland/qwaylandintegration.cpp b/src/plugins/platforms/wayland/qwaylandintegration.cpp
index 9158013fe78..d66710f4e55 100644
--- a/src/plugins/platforms/wayland/qwaylandintegration.cpp
+++ b/src/plugins/platforms/wayland/qwaylandintegration.cpp
@@ -56,6 +56,7 @@
 #include "qwaylandinputdeviceintegration_p.h"
 #include "qwaylandinputdeviceintegrationfactory_p.h"
 #include "qwaylandwindow_p.h"
+#include "qwaylandsessionmanager_p.h"
 
 #include <QtWaylandClient/private/qwayland-xdg-system-bell-v1.h>
 
@@ -529,6 +530,12 @@ QWaylandShellIntegration *QWaylandIntegration::createShellIntegration(const QStr
     }
 }
 
+QPlatformSessionManager *QWaylandIntegration::createPlatformSessionManager(const QString &id, const QString &key) const
+{
+    Q_UNUSED(key);
+    return new QWaylandSessionManager(mDisplay.data(), id);
+}
+
 void QWaylandIntegration::reset()
 {
     mServerBufferIntegration.reset();
diff --git a/src/plugins/platforms/wayland/qwaylandintegration_p.h b/src/plugins/platforms/wayland/qwaylandintegration_p.h
index d799555570d..04a0787d1ef 100644
--- a/src/plugins/platforms/wayland/qwaylandintegration_p.h
+++ b/src/plugins/platforms/wayland/qwaylandintegration_p.h
@@ -36,6 +36,7 @@ class QWaylandInputDevice;
 class QWaylandScreen;
 class QWaylandCursor;
 class QWaylandPlatformServices;
+class QWaylandSessionManager;
 
 class Q_WAYLANDCLIENT_EXPORT QWaylandIntegration : public QPlatformIntegration
 #if QT_CONFIG(opengl)
@@ -131,6 +132,7 @@ private:
     void initializeShellIntegration();
     void initializeInputDeviceIntegration();
     QWaylandShellIntegration *createShellIntegration(const QString& interfaceName);
+    QPlatformSessionManager *createPlatformSessionManager(const QString &id, const QString &key) const override;
 
     const QString mPlatformName;
     QScopedPointer<QPlatformFontDatabase> mFontDb;
diff --git a/src/plugins/platforms/wayland/qwaylandsessionmanager.cpp b/src/plugins/platforms/wayland/qwaylandsessionmanager.cpp
new file mode 100644
index 00000000000..9539bb15221
--- /dev/null
+++ b/src/plugins/platforms/wayland/qwaylandsessionmanager.cpp
@@ -0,0 +1,91 @@
+// Copyright (C) 2024 David Edmundson <[email protected]>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qwaylandsessionmanager_p.h"
+
+#ifndef QT_NO_SESSIONMANAGER
+
+#include "qwaylanddisplay_p.h"
+#include "qwaylandwindow_p.h"
+
+#include <private/qsessionmanager_p.h>
+#include <private/qguiapplication_p.h>
+
+#include <QtCore/QDebug>
+
+QT_BEGIN_NAMESPACE
+
+namespace QtWaylandClient {
+
+QWaylandSessionManager::QWaylandSessionManager(QWaylandDisplay *display, const QString &id)
+    : QObject(nullptr)
+    , QPlatformSessionManager(id, QString())
+    , mDisplay(display)
+{
+    if (!display->xxSessionManager())
+        return;
+
+    // The protocol also exposes a way of supporting crash handling to expose later
+    startSession();
+}
+
+QWaylandSession *QWaylandSessionManager::session() const
+{
+    return mSession.data();
+}
+
+QWaylandSessionManager *QWaylandSessionManager::instance()
+{
+    auto *qGuiAppPriv = QGuiApplicationPrivate::instance();
+    auto *managerPrivate = static_cast<QSessionManagerPrivate*>(QObjectPrivate::get(qGuiAppPriv->session_manager));
+    return static_cast<QWaylandSessionManager *>(managerPrivate->platformSessionManager);
+}
+
+void QWaylandSessionManager::setSessionId(const QString &id)
+{
+    m_sessionId = id;
+}
+
+void QWaylandSessionManager::startSession()
+{
+    QtWayland::xx_session_manager_v1::reason restoreReason = QtWayland::xx_session_manager_v1::reason_launch;
+    if (!sessionId().isEmpty()) {
+        restoreReason = QtWayland::xx_session_manager_v1::reason_session_restore;
+    }
+    mSession.reset(new QWaylandSession(this));
+    mSession->init(mDisplay->xxSessionManager()->get_session(restoreReason, sessionId()));
+    mDisplay->forceRoundTrip();
+}
+
+QWaylandSession::QWaylandSession(QWaylandSessionManager *sessionManager)
+    : mSessionManager(sessionManager)
+{
+}
+
+QWaylandSession::~QWaylandSession() {
+    // There's also remove which is another dtor
+    // depending on whether we're meant to clean up server side or not
+    // we might need to expose that later
+    destroy();
+}
+
+void QWaylandSession::xx_session_v1_created(const QString &id) {
+    qCDebug(lcQpaWayland) << "Session created" << id;
+    mSessionManager->setSessionId(id);
+}
+
+void QWaylandSession::xx_session_v1_restored() {
+    qCDebug(lcQpaWayland) << "Session restored";
+    // session Id won't have change, do nothing
+}
+
+void QWaylandSession::xx_session_v1_replaced() {
+    qCDebug(lcQpaWayland) << "Session replaced";
+    mSessionManager->setSessionId(QString());
+}
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/plugins/platforms/wayland/qwaylandsessionmanager_p.h b/src/plugins/platforms/wayland/qwaylandsessionmanager_p.h
new file mode 100644
index 00000000000..aa9e0eec001
--- /dev/null
+++ b/src/plugins/platforms/wayland/qwaylandsessionmanager_p.h
@@ -0,0 +1,71 @@
+// Copyright (C) 2024 David Edmundson <[email protected]>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QWAYLANDSESSIONMANAGER_H
+#define QWAYLANDSESSIONMANAGER_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#ifndef QT_NO_SESSIONMANAGER
+
+#include <QtGui/qpa/qplatformsessionmanager.h>
+#include <QtWaylandClient/qtwaylandclientglobal.h>
+#include <QtWaylandClient/private/qwayland-xx-session-management-v1.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QtWaylandClient {
+
+class QWaylandDisplay;
+class QWaylandWindow;
+class QWaylandSession;
+class QWaylandSessionManager;
+
+
+class Q_WAYLANDCLIENT_EXPORT QWaylandSession : public QObject, public QtWayland::xx_session_v1
+{
+    Q_OBJECT
+public:
+    QWaylandSession(QWaylandSessionManager *sessionManager);
+    ~QWaylandSession();
+
+protected:
+    void xx_session_v1_created(const QString &id) override;
+    void xx_session_v1_restored() override;
+    void xx_session_v1_replaced() override;
+private:
+    QWaylandSessionManager *mSessionManager;
+};
+
+class Q_WAYLANDCLIENT_EXPORT QWaylandSessionManager : public QObject, public QPlatformSessionManager
+{
+    Q_OBJECT
+public:
+    static QWaylandSessionManager *instance();
+    QWaylandSessionManager(QWaylandDisplay *display, const QString &id);
+
+    QWaylandSession* session() const;
+private:
+    void setSessionId(const QString &id);
+    void startSession();
+
+    QWaylandDisplay *mDisplay = nullptr;
+    QScopedPointer<QWaylandSession> mSession;
+    friend class QWaylandSession;
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
+#endif
diff --git a/src/plugins/platforms/wayland/qwaylandwindow.cpp b/src/plugins/platforms/wayland/qwaylandwindow.cpp
index 73d90b6c321..cfbc392c319 100644
--- a/src/plugins/platforms/wayland/qwaylandwindow.cpp
+++ b/src/plugins/platforms/wayland/qwaylandwindow.cpp
@@ -1,6 +1,7 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#include "qwaylandsessionmanager_p.h"
 #include "qwaylandwindow_p.h"
 
 #include "qwaylandbuffer_p.h"
@@ -1934,6 +1935,16 @@ QSurfaceFormat QWaylandWindow::format() const
     return mSurfaceFormat;
 }
 
+void QWaylandWindow::setSessionRestoreId(const QString &role)
+{
+    mSessionRestoreId = role;
+}
+
+QString QWaylandWindow::sessionRestoreId() const
+{
+    return mSessionRestoreId;
+}
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/wayland/qwaylandwindow_p.h b/src/plugins/platforms/wayland/qwaylandwindow_p.h
index 5ad826018bb..23c5ed04b8f 100644
--- a/src/plugins/platforms/wayland/qwaylandwindow_p.h
+++ b/src/plugins/platforms/wayland/qwaylandwindow_p.h
@@ -252,6 +252,8 @@ public:
     bool windowEvent(QEvent *event) override;
 
     QSurfaceFormat format() const override;
+    void setSessionRestoreId(const QString &role) override;
+    QString sessionRestoreId() const;
 
 public Q_SLOTS:
     void applyConfigure();
@@ -346,6 +348,7 @@ protected:
     QWaylandShmBackingStore *mBackingStore = nullptr;
 
     QMargins mCustomMargins;
+    QString mSessionRestoreId;
 
     QPointer<QWaylandWindow> mTransientParent;
     QList<QPointer<QWaylandWindow>> mChildPopups;
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 1155172a0a8..22ca1d238fe 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -1360,6 +1360,12 @@ void QWidgetPrivate::create()
             xcbWindow->setWindowRole(topData()->role);
     }
 #endif
+#if QT_CONFIG(wayland)
+    if (!topData()->role.isNull()) {
+        if (auto *waylandWindow = dynamic_cast<QWaylandWindow*>(win->handle()))
+            waylandWindow->setSessionRestoreId(topData()->role);
+    }
+#endif
 
     QBackingStore *store = q->backingStore();
     usesRhiFlush = false;
@@ -6359,17 +6365,24 @@ QString QWidget::windowRole() const
 */
 void QWidget::setWindowRole(const QString &role)
 {
-#if QT_CONFIG(xcb)
+#if QT_CONFIG(xcb) || QT_CONFIG(wayland)
     Q_D(QWidget);
     d->createTLExtra();
     d->topData()->role = role;
+#else
+    Q_UNUSED(role);
+#endif
+
     if (windowHandle()) {
+#if QT_CONFIG(xcb)
         if (auto *xcbWindow = dynamic_cast<QXcbWindow*>(windowHandle()->handle()))
             xcbWindow->setWindowRole(role);
-    }
-#else
-    Q_UNUSED(role);
 #endif
+#if QT_CONFIG(wayland)
+        if (auto *waylandWindow = dynamic_cast<QWaylandWindow*>(windowHandle()->handle()))
+           waylandWindow->setSessionRestoreId(role);
+#endif
+    }
 }
 
 /*!